A few years back I painted our cedar / pressure treated deck with Olympic water based, opaque deck stain. It held up where the wood was good, but where the wood was weather damaged the paint lost it's adhesion sooner than expected. So, this summer, I've been experimenting with the best way to get the loose stuff off.
I started with just the garden hose. It blew off loose paint pretty easily but I could see there was still more that was curled and flaked. So, I picked up an electric power washer (Karcher)
at Wal*mart (imagine that - a German engineered product at Made in China ™) for $98. It works really well and came with two wands, a powerful 1500 psi fan wand and and insane rotating pencil brush wand that I can only imagine would destroy the wood on the deck completely.
As it is, the problem with the paint coming loose to begin with is due to moisture getting between the paint and the wood. So, where there are places on the deck where the paint is still good, the high pressure spray worked to compromise some of this paint over time. I learned this when I followed up my spraying with a push style wire brush to get any remaining loose bits and then a bleach wash to prepare the wood for painting. I think the bleach worked to further loosen paint as well for, when I set about rinsing down the deck with just the garden hose, more paint came flying off.
My goal had been to keep what was good and paint over it rather than strip the entire surface area of the deck. I decided I needed a better, more thorough way to get all the paint off. So, I picked up a $19 heat gun and tried that. It only served to scorch the wood while it melted the paint. And it was taking a really long time.
Last bet - a rotary wire brush attachment for my power drill (fine grade.) This does a quick and terrific job of getting to genuinely loose paint while burnishing the good paint down at the edges. I think this is probably the most effective, non chemical, way to strip paint from soft wood. The only down side is, well, you have to BE down to use it - on your knees or sitting. No standing up like with the power washer. As such, it's a huge pain for me and my lousy back. Fortunately, I have a couple younger guys I know who don't terribly mind a little hard work in exchange for cash, so hopefully I'll have some help here shortly.
Next time, I'll tell you about the paint I found out about. It's not cheap, but it is very very good.